Method and apparatus for locating mobile assets

ABSTRACT

A system for locating mobile assets includes a plurality of fixed mesh network communications devices, an asset-specific location device, and a computer. Each fixed mesh network communications device is associated with a different location within a predefined area. The asset-specific location device is coupled to the mobile assets and communicates an asset-specific identification to a nearest fixed mesh network communications device via a mesh network. The computer is in communication with each of the fixed mesh network communications devices and receives a request for a location of one of the mobile assets; polls each fixed mesh network communications device to determine which one is in communication with a selected asset-specific location device affixed to the selected mobile asset; and identify the location associated with the fixed mesh network communications device in communication with the asset-specific location device.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of, and claims the benefitof, U.S. patent application Ser. No. 11/422,461, filed Jun. 6, 2006,which is a continuation-in-part of U.S. patent application Ser. No.11/369,162, filed Mar. 7, 2006, now issued as U.S. Pat. No. 7,451,927,which is a continuation-in-part of U.S. patent application Ser. No.11/303,791, filed Dec. 16, 2005, now issued as U.S. Pat. No. 7,416,123,the entirety each of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to locating systems and, morespecifically, to a system of locating a mobile asset within a predefinedarea.

2. Description of the Prior Art

With increases in global travel and trade, misdirection of transporteditems causes substantial hardship to those who are transporting suchitems and substantial cost to those responsible for the transport ofsuch items. When an item cannot be found, insurance providers also beara cost. For example, airlines misdirect many pieces of luggage eachyear. Finding lost luggage causes considerable inconvenience to thepassengers whose luggage is lost and considerable expense to the airlinethat misdirected the luggage.

One method of preventing misdirection of luggage includes attaching abar-coded tag to each piece of luggage as the owner checks in for aflight. The tag is scanned at the point of departure and at the point ofarrival (and any intermediate points) and the location of the luggage isstored in a computer database. While such a tracking system has beenquite effective in reducing the incidence of lost luggage, luggage stillgets misdirected. This can occur for one of several reasons, includingairline ticketing counter attendant error resulting in an incorrect tagbeing applied to a piece of luggage. Also, a tag can be inadvertentlyremoved from a piece of luggage during the handling process.

This problem is also significant in other areas. For example,international freight transport typically involves sending containers oncontainer ships. The containers often include exterior bar-coded labelsused for tracking purposes. However, containers can be misdirectedthrough operator error. When a container is misdirected, the cost offailing to locate it quickly can be substantial.

Certain existing and proposed location systems include devices thatapply a radio transponder, such as an RFID tag, to the item beingtransported. When an item is lost, a message is sent to eachtransportation node where the item could be sent and an operator with acorresponding radio frequency device searches through the node seeking areturn signal indicating the presence of the lost item. Such systemshave the disadvantage of requiring a considerable amount of time to bespent by personnel at each node, including all of the nodes to which theitem was not spent.

Recently, that has been an increasing need for improved securityrelating to luggage and containers being imported. One method ofensuring security is to check each item in a cargo hold against ashipping manifest, thereby ensuring that exactly the items to betransported are in the cargo hold. However, such checking can be timeconsuming and not practical when, as with a scheduled flight, delays maycause scheduling problems and economic loss to the carrier.

Also, many people are concerned with increased smuggling of contraband(such as narcotics weapons materials). However, with most cargooperations, inspecting each container entering a port is quitedifficult. Contraband sensor systems disposed in containers have notbeen effective because the containers that are placed under layers ofother containers are usually shielded from central communicationservers, thereby preventing a communication link between the most remotecontainers and the central server.

There are many types of mobile assets, such as wheel chairs at anairport, shopping carts at a store, rental bicycles or short use rentalcars, etc. Such mobile assets may be used by many different people atdifferent times. Often a person uses a mobile asset and then leaves itat a random location. For example, many cities have short use—one waycar rental agencies, in which a vehicle is picked up by a user in onelocation in the city and left at another location. Efficient use of suchmobile assets requires that the assets can be easily located. Currentlocation systems involve manual reporting of the asset locations, whichis time consuming and unreliable.

Therefore, there is a need for a system that facilitates automaticlocation of mobile assets.

SUMMARY OF THE INVENTION

The disadvantages of the prior art are overcome by the present inventionwhich, in one aspect, is an apparatus for identifying items in a cargohold, having an entrance that is accessible by a user, wherein each ofthe items includes an individual mesh network communication device andwherein each individual mesh network communication device including amemory that stores a unique item identification. The apparatus includesa primary mesh network communications device and a portablecomputational device in data communication with the primary mesh networkcommunication device. A frame separates the primary mesh networkcommunications device from the portable computational device at adistance that enables the user to hold the portable computational deviceand to direct the mesh network communications device to the entrance ofthe cargo hold.

In another aspect, the invention is a shipping container that includes aplurality of walls, in which each wall has an interior surface and anexterior surface. A container mesh network communication device isaffixed to the interior surface of a selected wall of the plurality ofwalls. An antenna is in communication with the container mesh networkcommunication device and is affixed to the exterior surface of theselected wall.

In another aspect, the invention is a system for monitoring a shippingcontainer that includes a sensor array disposed within the container.The sensor array is configured to detect at least one environmentalparameter within the shipping container and to generate an indication ofthe environmental parameter. A container mesh network communicationdevice is in communication with the sensor array and is responsive tothe indication of the environmental parameter. The container meshnetwork communication device is configured to store a unique containeridentification. A container polling unit is in wireless communicationwith the container mesh network communication device and is configuredto poll the container mesh network communication device and to receivetherefrom the indication of the environmental parameter and the uniquecontainer identification. The container polling unit is also configuredto generate an indication signal corresponding to the environmentalparameter. A communication device is in communication with the containerpolling unit and transmits the indication signal to a remote receiver.

In another aspect, the invention is a method of verifying a cargomanifest for a cargo hold in which a plurality of items are disposed inthe cargo hold and in which each of the plurality of items has anindividual mesh network communication device associated therewith and inwhich each individual mesh network communication device stores a uniqueitem identification. In the method, the cargo manifest, including aunique manifest identification corresponding to each item on the cargomanifest, is downloaded to a portable computing device. A polling signalis transmitted using a primary mesh network communication device that iscontrolled by the portable computing device. The corresponding uniqueitem identification is received from each individual mesh networkcommunication device and each unique item identification in an item listis stored. Each unique item identification received is compared to eachunique manifest identification. An indication of each mismatch betweenthe cargo manifest and the item list. is generated.

In another aspect, the invention is a method of monitoring a cargocontainer on a carrier, in which a polling request message istransmitted to a container mesh network communications device associatedwith the container. Container-specific information is received from thecontainer mesh network communications device in response to the pollingrequest. A polling signal is received from a remote requester, in whichthe polling signal includes a carrier identification. The carrieridentification is compared to a stored identification and, if thecarrier identification is identical to the stored identification, thenthe container-specific information is transmitted to the remoterequester.

In another aspect, the invention is a system for locating mobile assetswithin a predefined area that includes a plurality of fixed mesh networkcommunications devices, an asset-specific location device, and acomputer. Each of the plurality of fixed mesh network communicationsdevices is associated with a different predetermined location within thepredefined area. The asset-specific location device is coupled to atleast one of the mobile assets and is configured to communicate anasset-specific identification to a nearest one of the plurality of fixedmesh network communications devices via a mesh network. The computer isin communication with each of the fixed mesh network communicationsdevices and is configured to: receive from a user a request for alocation of a selected one of the mobile assets; poll each of theplurality of fixed mesh network communications devices to determinewhich one of the plurality of fixed mesh network communications devicesis in communication with a selected asset-specific location device thatis affixed to the selected one of the mobile assets; and identify to theuser the predetermined location associated with the fixed mesh networkcommunications device that is in communication with the selectedasset-specific location device.

In another aspect, the invention is a system for locating mobile assetswithin an airport. A plurality of fixed mesh network communicationsdevices is disposed in a different area of the airport. A wheel chair iscoupled to a wheel chair-specific location device. The wheelchair-specific location device is configured to communicate a wheelchair-specific identification to a nearest one of the plurality of fixedmesh network communications devices via a mesh network. Each wheelchair-specific location device includes a power source, a mesh networkcommunication device electrically coupled to the power source, a memorycircuit that stores the wheel chair-specific identification and aprocessor. The processor is electrically coupled to the power source andis in communication with the memory circuit and the mesh networkcommunication device. The processor is programmed to execute thefollowing steps: if a wheel chair identification message is receivedfrom the fixed mesh network communication device, then compare a wheelchair identification included in the wheel chair identification messageto the wheel chair-specific identification stored in the memory; andwhen the wheel chair identification included in the wheel chairidentification message corresponds to the wheel chair-specificidentification stored in the memory, then transmit a wheel chair foundmessage to the fixed mesh network communication device. A computer, incommunication with each of the fixed mesh network communications devicesis configured to: receive from a user a request for a location of aselected wheel chair; poll each of the plurality of fixed mesh networkcommunications devices to determine which of the plurality of fixed meshnetwork communications devices is in communication with a selected wheelchair-specific location device that is in affixed to the selected one ofthe wheel chairs; and identify to the user the predetermined locationassociated with the fixed mesh network communications device that is incommunication with the selected wheel chair-specific location device.

In yet another aspect, the invention is a method of locating mobileassets within a predefined area, in which an asset identification istransmitted from a central station to a plurality of fixed mesh networkcommunications devices associated with a different predeterminedlocation within the predefined area. The asset identification istransmitted from each fixed mesh network communications device. Aresponse is received at one fixed mesh network communication device fromat least one asset-specific location device affixed to at least one ofthe mobile assets. The response indicates that the at least oneasset-specific location device has stored therein the assetidentification. An indication that the one fixed mesh networkcommunication device has received the asset identification from the atleast one asset-specific location device is transmitted from the onefixed mesh network communication device to the central station.

These and other aspects of the invention will become apparent from thefollowing description of the preferred embodiments taken in conjunctionwith the following drawings. As would be obvious to one skilled in theart, many variations and modifications of the invention may be effectedwithout departing from the spirit and scope of the novel concepts of thedisclosure.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

FIG. 1 is a schematic diagram of a system according to one illustrativeembodiment of the invention.

FIG. 2A is a block diagram of one embodiment of a mesh network locationdevice.

FIG. 2B is a flow diagram of one representative method that may beemployed in the mesh network location device shown in FIG. 2A

FIG. 3 is a schematic diagram of one embodiment of the invention beingemployed in a luggage storage room.

FIG. 4 is a flow diagram of a method that may be employed in a computerat a node.

FIG. 5 is a schematic diagram of one embodiment of the inventioninteracting with a global positioning satellite and a wirelesscommunications system.

FIG. 6 is a simplified flow diagram of a method that may be employed ina mode of operation that interacts with a global positioning satelliteand a wireless communications system.

FIG. 7 is a detailed flow diagram of one embodiment of a method that maybe employed with the invention.

FIG. 8 is a schematic diagram of an embodiment used to detect thepresence of items in a cargo hold.

FIG. 9A is a diagram showing use of the embodiment shown in FIG. 8.

FIG. 9B is a diagram showing an alternative use of the embodiment shownin FIG. 8.

FIG. 10 is a diagram showing communication between the embodiment shownin FIG. 8 and a computer server.

FIG. 11 is a flowchart showing one method for comparing the contents ofa manifest to the items in a cargo hold.

FIG. 12 is a plan view of one embodiment being employed in a cargo shipapplication.

FIG. 13 is a schematic diagram and a detail of a shipping container.

FIG. 14 is a schematic diagram of a sensor array embodiment employed ina container.

FIG. 15 is a block diagram of a sensor array embodiment.

FIG. 16 is an elevational view of a cargo ship employing one embodiment.

FIG. 17 is a flow chart that shows a polling routine.

FIG. 18 is a schematic diagram of a mobile asset location system.

FIG. 19 is a schematic diagram of a mobile asset location systememployed in an airport.

FIG. 20 is a schematic diagram of a mobile asset location system adaptedfor use with shopping carts and the like.

FIG. 21 is a schematic diagram of a mobile asset location systememployed in a store and a surrounding parking lot.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the invention is now described in detail.Referring to the drawings, like numbers indicate like parts throughoutthe views. Unless otherwise specifically indicated in the disclosurethat follows, the drawings are not necessarily drawn to scale. As usedin the description herein and throughout the claims, the following termstake the meanings explicitly associated herein, unless the contextclearly dictates otherwise: the meaning of “a,” “an,” and “the” includesplural reference, the meaning of “in” includes “in”and “on.” Also, asused herein, “global computer network” includes the Internet.

As shown in FIG. 1, one illustrative embodiment of the invention is asystem 100 for locating lost items, such as luggage. In the system 100,a plurality of different transportation nodes 104 a-f (such as airports,train stations, shipping terminals, etc.) communicate with each othervia a global computer network 102. In one illustrative embodiment of theinvention employed in aviation, when a traveler arrives at an airport(e.g., airport 104 d) and notices that a piece of luggage is missing, hecan go to a lost luggage representative for the airline on which hetraveled to report the missing luggage. The lost luggage representativesends a message to all of the other airports in the system 100identifying the lost piece of luggage. A search for the lost piece ofluggage is performed at each airport using the system described below.If the piece of lost luggage is found at an airport (e.g., airport 104b) then a signal is sent from a computer at the airport 104 b to thedestination airport 104 d indicating that the piece of luggage has beenfound and identifying the airport at which it has been found.

A device 200 used in identifying luggage is shown in FIG. 2A. Each pieceof luggage that employs the system would include one of these devices200 disposed therein. The device 200 includes a mesh networkcommunication device 210 that is powered by a power source 216. Aprocessor 212 is also powered by the power source 216 and is in datacommunication with a memory 214 and the mesh network communicationdevice 210. The processor 212 could be a standard on-boardmicroprocessor or microcontroller. The memory stores, inter alia, aunique identification. The unique identification could take the form ofa sequence of bits that uniquely identify a specific device 200 withrespect to all other similar devices in the system.

The power source 216 could include a battery (such as the thin filmbattery shown) or another type of power source, such as a micro fuelcell, a super capacitors, etc. One source of suitable thin-filmbatteries is Excellatron Solid State LLC, 263 Decatur Street, Atlanta,Ga. 30312.

In one exemplary embodiment, any one of several commercially-availableZigBee®devices may be used for the mesh network communication device210. ZigBee® is a published specification set of high levelcommunication protocols designed to use small, low power digital radiosbased on the IEEE 802.15.4 standard for wireless personal area networks.In one embodiment, the device 210 employs the 802.14.5—IEEE MAC Layer asthe radio specification for communications and uses the ZigBee® protocol(firmware stack) to govern the utilization of the radio. In one example,the device 210 operates in the 2.4 GHz band but could also have thecapability to operate in 868 MHz as well as the 900 MHz bands.Typically, 868 MHZ has been designated for European operations, whereas900 MHz has been authorized for operation in North America. Currently,2.4 GHz is accepted world-wide as an acceptable frequency. In oneillustrative mode, the device 210 will communicate in a STAR andPeer-to-Peer network topology. Such networks, sometimes referred to as“mesh networks” or “ad-hoc networks” are self-discovering, self-formingand self-healing.

The processor 212 is programmed to execute several steps, as shown inthe flow chart 220 shown in FIG. 2B. Initially, the system waits untilan item identification message is received 222 from the fixed meshnetwork communication device. Then the processor 212 compares 224 theunique item identification to the unique item-specific identification.If the unique item identification corresponds to the uniqueitem-specific identification, then the system transmits 226 the itemidentified message via the mesh network communication device 210.

Typically, as shown in FIG. 3, lost luggage is stored in a luggagestorage area 320 at an airport. A system 300 used to find lost luggage,according to one illustrative embodiment of the invention, could includea computer 310 in communication with the global computer network 102 anda fixed mesh network communications device 330 that is disposed in theluggage storage area 320. Several other fixed mesh networkcommunications devices 332 may also be located in the luggage storagearea 320, to serve as passive relays. While some pieces of luggage 340may not participate in the luggage location system, pieces of luggage342 that do would have item-specific location device 200 disposedtherein.

Each of the fixed mesh network communications devices 330 and 332 andthe item-specific location devices 200 are able to communicate with eachother and can form an ad-hoc mesh network 336 when they are within rangeof each other. When the computer receives an item identification messagefrom the global computer network 102, it transmits an itemidentification message to fixed mesh network communications device 330.The item identification message will include a unique identification ofa piece of luggage that has been lost and that is sought by therequester. The fixed mesh network communications device 330 thentransmits an item identification message (including the uniqueidentification of the piece of lost luggage being sought) to theitem-specific location devices 200 and fixed mesh network communicationsdevices 332 within range. Each item-specific location device 200 andfixed mesh network communications device 332 retransmits the itemidentification message to surrounding item-specific location devices 200and fixed mesh network communications devices 332. Also, each of theitem-specific location devices 200 compares the identification of thepiece of lost luggage being sought to the unique identification storedin its memory. If one of the item-specific location devices 200 hasstored therein the identification of the piece of lost luggage beingsought, it sends a luggage identified message to the computer via themesh network 336. The computer 310 then sends to the requester via theglobal computer network 102 a message indicating that the piece ofluggage has been found and an indication of which airport it has beenfound at.

Once it is determined that the piece of lost luggage is in a specificluggage storage area 320 at an airport, the specific location of thepiece of luggage within the luggage storage area 320 may then bedetermined by one of several methods. In one simple method, an operatorcan move throughout the luggage storage area 320 looking for a piece ofluggage that matches the description of the lost piece of luggage. Also,a hand-held mesh network communications device can be moved throughoutthe luggage storage area 320 continually sending out queries for thelost piece of luggage. If the hand-held device is equipped with a signalstrength indicator, then the operator would move through luggage storagearea 320 until maximum received signal strength is detected.

As shown in FIG. 4, in one illustrative embodiment, the computer 310 maybe programmed to determine 421 if a luggage identification request hasbeen received from a requester via the global computer network (GCN).Once a luggage identification request has been received, then thecomputer sends 414 a luggage identification message to the fixed meshnetwork communication device (Fixed MND). If a luggage identifiedmessage is received 416 from the fixed mesh network communication devicein response to the luggage identification message indicating that theluggage-specific location device corresponds to the requested luggageidentification, then the computer transmits 418 to the requester, viathe global computer network, a luggage identified notification and alocation identification that identifies the transportation node.

One embodiment is an item location apparatus 500 that includes a meshnetwork communication device 516, a global positioning satellite chipset514 that can receive location data from a global positioning satellitesystem 502, a cellular telecommunications modem 518 that can communicatewith a wireless network 504, and a digital memory 512 that stores aunique identification. The mesh network communication device 516 iscapable of communicating with a remote mesh network communication system506 that is in communication with a global computer network 102. Aprocessor 510 is in digital communication with the mesh networkcommunication device 516, the global positioning satellite chipset 514,the cellular telecommunications modem 518 and the memory 512. All ofthese elements could be powered by a power source such as a thin filmbattery.

As shown in FIG. 6, in operation, the system first determines 610 if ita mesh network is within range and, if the result is “yes” then thesystem will operate in a mesh network mode 612, in which the systemcommunicates with the mesh network. If the result is “no,” then thesystem will sample the local cellular environment 614 to determine if itcan communicate with a local wireless communications cell. The systemalso determines its current location 616 based on an input from the GPSchipset and it logs the current location 618 in the digital memory. Bylogging the location, the system can communicate the last known locationin the situation when the system is outside of communication range ofall GPS satellites.

The system determines if it is being polled by a cellular network 620and, if not, it will return to step 614. If the system is being polled,by a requester requesting the location of the object identified by theunique identification, then it will transmit 622 the location of theobject and the unique identification to the requester.

In another embodiment of the method 700 employed by the system, as shownin FIG. 7, when the system powers on 702 it starts a cycle in which itdetermines 710 if a mesh network is available. If one is available, itdetermines 712 whether a GPS constellation is suitably in view to allowlocation of the object with the GPS chipset. If no GPS constellation isin view, then the system will power down the GPS chipset for apredetermined period of time 728, to reduce drain on the battery, andreturn to step 710. Also, irrespective of the result of step 712 thesystem will determine whether it is authorized to communicate with thelocal mesh network 714. If the system is authorized then it will operatein a mesh network mode 716 in which it will communicate with the meshnetwork. It will also provide GPS location data for the object if suchdata is available. If the result of either step 710 or step 714 is“no,”then the system will determine if a GPS constellation is suitablyin view 726 and, if the result is “no,” the system will go to step 728.Otherwise, the system will begin logging the geographic location of theobject 730 and will continue to log the current location periodically.If requested, the system will send location data to a head end 732 orother authorized requester transmitting a request for a location of theobject.

If the result of step 710 is that no mesh network is available, then thesystem will periodically sample 718 the cellular telephone environmentto search for a mobile telephone cell within range that the system isauthorized to communicate with. Once such a cell is found, the systemwill register with the cell network 720 and listen 722 for any requestsfor a location of the object received from the network. The system willthen respond to any such requests 724 for a location of the object bytransmitting the GPS location data (or the last known location that waslogged into the memory if no GPS satellite is in view).

While the disclosed embodiment discusses use of the invention in asystem for locating lost luggage at airports (or other types oftransportation nodes, such as train stations, bus stations, etc.) theinvention could be used in many other applications. For example, theinvention could be used for locating lost shipping containers, lostnotebook computers, lost pets, etc. It could also be used as part of asupply chain management system to track lost orders and even forperforming inventory functions. For example, a company could performremote inventories of its warehouses using the invention. The inventioncould also be used in vehicle fleet management systems, allowing a fleetmanager to inventory the location of each of its vehicles remotely. Ascan be seen, given that some mesh network devices are relativelyinexpensive, the invention can be used in many applications and it isintended that the claims below apply to all such applications.

In one embodiment of the invention, a device may be employed to sensethe presence of luggage and other items employing a mesh networkcommunication device of the type described above. As shown in FIG. 8,the device 800 could include a personal data assistant 810, or otherportable computer, that is spaced apart from a mesh networkcommunication device 816 with a tube 812, or other type of rigid framestructure. A data channel 814 (such as a pair of wires) connects thepersonal data assistant 810 to the mesh network communication device 816and can run through the center of the tube 812.

In use, as shown in FIG. 9A, the mesh network communication device 816is placed near an entrance to a cargo hold 912 such as in a airplane 910and the mesh network communication device 816 will establish acommunications tunnel with at least one of the mesh networkcommunication devices 916 and, thereby, set up an ad-hoc network withthe mesh network communication devices 916 associated with each piece ofluggage 914 inside the cargo hold 912. The mesh network communicationdevices 916 associated with each piece of luggage 914 could either beplaced inside the corresponding piece of luggage 914 or be affixed toits exterior.

Not only can this embodiment be used to find lost luggage, but it canalso be used to verify quickly that all luggage 914 in the cargo hold912 is listed on the manifest for a flight, and that all luggage 914 onthe manifest is in the cargo hold 912. In an alternate embodiment, asshown in FIG. 9B, the cargo hold can be fitted with a fixed mesh networkcommunication device 920 that is hard wired to a communication port 922that facilitates communication with the personal data assistant 810. Thecommunication port 922 could be one of many, such as a “one-wire” dataport (e.g., an “I-Button” data port available from DallasSemiconductor). As shown in FIG. 10, the manifest may be downloaded froma server 1010 to the personal data assistant 810 through use of awireless communication port 818 coupled to the personal data assistant810.

As shown in FIG. 11, one method of checking a manifest includes firstdownloading the cargo manifest 1102 into the memory of the personal dataassistant 810, and then polling the cargo hold 1104. In the pollingstep, a message is sent to at least one of the mesh networkcommunication devices within the cargo hold, thereby setting up an adhoc network between all of the mesh network communication devices withinthe cargo hold. Each item, once contacted, transmits its unique itemidentification to the personal data assistant 810 and each unique itemidentification is then stored in an item list. The item list is thencompared to the manifest. First, a counter for tracking retrieval ofmanifest records is reset 1105 and then a test 1106 determines if thelast record has been retrieved from the manifest. If not, then the nextrecord is retrieved 1108 from the manifest and a counter that tracksretrieval of records on the item list is reset 1109. A test 1110 thendetermines if the last record has been retrieved from the item list. Ifnot, then the next item is retrieved 1112 from the item list and thecurrently retrieved item is compared 1114 to the current item from themanifest and if they are the same, both the current item list itemrecord and the current manifest item record are flagged 1116 to indicatethat they are accounted for. Otherwise, control passes back to step1110. Once every item in the item list has been compared, control passesto step 1106 to retrieve the next item on the manifest list. Once allitems have been compared, then a list is generated 1118 in which eachitem on either the item list or the manifest list that is not pared witha corresponding item on the other list is listed. This list indicateseither missing luggage or the presence of luggage not belonging to apassenger and can be used to prompt an investigation into the reason forthe differing lists.

As shown in FIG. 12, one embodiment of the invention can be used tomonitor cargo containers 1210 in the cargo hold of a container ship1200. Each container includes a mesh network communications device 1212that includes a unique identification-storing memory. As shown in FIG.13, in one embodiment, the mesh network communication device 1212 may beused to monitor the items 1310 inside the container 1210, wherein eachitem is fitted with its own mesh network communication device 1312. Inone embodiment, the container mesh network communication device 1212 maybe disposed inside the container 1210, with an antenna 1320 extendingoutside the container 1210 through an opening in the wall of thecontainer 1210. In another embodiment, where only containers aretracked, the container mesh network communication device 1212 may beaffixed to, and entirely disposed outside of the container 1210.

As shown in FIGS. 14-16, one embodiment of the invention may be used tomonitor the contents of a container 1210 to detect environmentalconditions inside of the container 1210. Such an embodiment could beused to detect the presence of hazardous substances or to logtemperatures in refrigerated containers to ensure that quality ismaintained during transit. To accomplish these goals, a sensor array1412 is coupled to the container mesh network communication device 1212.The sensor array could include one or more sensors, for example:radiation detectors, explosive detectors, chemical sensors, biologicalsensors, temperature sensors, pressure sensors, humidity sensors and thelike. To ensure the integrity of the system, the door to the container1210 could be fitted with a container access sensor 1414 that indicateswhether the door has been opened or a seal (which could be applied oncethe container has been fully loaded) has been tampered with.

As shown in FIGS. 15-16, one embodiment communicates with a satellite1502 (such as a low Earth orbiting satellite, for example a satellitewhose services can be contracted through ORBCOMM, 21700 AtlanticBoulevard, Dulles, Va. 20166 USA). This embodiment includes a containerpolling unit 1500 that could be mounted on a container ship 1200. Thecontainer polling unit 1500 could include a processor 1510 that is incommunication with the sensor array 1412 and the sealed container sensor1414, and that communicates with a polling unit mesh networkcommunication device 1512 and a satellite modem 1514, which in turncommunicates with a satellite transmitter 1516. (It should be noted thatthe satellite modem 1514 and the satellite transmitter 1516 could be asingle unit). One example of such a modem includes the Stellar ST2500,available from AirIQ Inc., 1099 Kingston Road Suite 233, Pickering, ONCanada L1V 1B5. The transmitter 1516 would be coupled to an antenna 1614to facilitate communication with the satellite 1502. The polling meshnetwork communication device 1512 would communicate with one or more ofthe item-specific mesh network communications devices 1212 associatedwith the individual containers.

In one method of operation, shown in FIG. 17, the container pollingsystem 1500 would poll 1710 the containers 1210 periodically to receiveinformation regarding the environmental conditions within each container1210. When a request from an authorized satellite is received 1712, areceived ship identification would be compared to a stored shipidentification (stored in a memory associated with the processor 1510)and if they are determined to be the same 1716 then the containerpolling system 1500 would transmit 1718 some or all of the containerinformation received in the polling step 1710 to the satellite.

The information could be processed by a remote receiver (havingdownloaded the information from the satellite) using known telematicstechnology techniques. In one embodiment, a report regarding theenvironment within any given container can be generated and transmittedto a user via a computer network, such as a global computer network. Inone embodiment, the invention allows for near continuous tracking of acontainer and its contents during every stage of transport. A detailedreport of the container's locations and the state of its internalenvironment may be generated. Such a report may be used to certify thecontainer's contents and environment for both security purposes andquality control.

As shown in FIG. 18, a mobile asset 1804, such as a wheelchair or otherpersonal mobility device, may be fitted with an asset-specific locationdevice 1820 that is configured to communicate in a mesh network. Theasset-specific location device 1820 may be attached to the mobile asset1804 or embedded therein. The asset-specific location device 1820communicates with a nearest fixed mesh network communications device1810, which can be mounted, for example, on a wall 1802.

As shown in FIG. 19, this embodiment can be employed in an airport 1900having several concourses 1902 wherein each concourse 1902 has at leastone fixed mesh network communications device 1810 associated therewith.When a user wants to determine the locations of the mobile assets 1804,a request is sent from a central computer to each of the fixed meshnetwork communications devices 1810, which communicate the request toeach of the asset-specific location devices 1820. Each of theasset-specific location devices 1820, send an identification to thenearest fixed mesh network communications device 1810, which thenindicates to the central computer the concourse where each mobile asset1804 may be found.

As shown in FIGS. 20 and 21, the mobile asset 2004 can be a shoppingcart that could be located in a store 2006 or in a parking lot 2008. Thefixed mesh network communications devices 1810 could be disposed in thestore 2006 and about the parking lot on, for example, light poles 2002.

In other examples, the mobile assets could include automobiles in adealership lot. The mobile assets could include bicycles (such as rentalbicycles), in a city with fixed mesh network communications devicedisposed around the city to keep track of the bicycle locations. Otherexamples of mobile assets include forklifts and flat and mobile carts ofthe type used in large hardware stores. It is intended that all of theseembodiments fall within the scope of the invention.

The above described embodiments, while including the preferredembodiment and the best mode of the invention known to the inventor atthe time of filing, are given as illustrative examples only. It will bereadily appreciated that many deviations may be made from the specificembodiments disclosed in this specification without departing from thespirit and scope of the invention. Accordingly, the scope of theinvention is to be determined by the claims below rather than beinglimited to the specifically described embodiments above.

1. A system for locating mobile assets within a predefined area,comprising: a. a plurality of fixed mesh network communications deviceseach associated with a different predetermined location within thepredefined area; b. an asset-specific location device coupled to atleast one of the mobile assets and configured to communicate anasset-specific identification to a nearest one of the plurality of fixedmesh network communications devices via a mesh network; and c. acomputer, in communication with each of the fixed mesh networkcommunications devices, that is configured to: i. receive from a user arequest for a location of a selected one of the mobile assets; ii. polleach of the plurality of fixed mesh network communications devices todetermine which one of the plurality of fixed mesh networkcommunications devices is in communication with a selectedasset-specific location device that is in affixed to the selected one ofthe mobile assets; and iii. identify to the user the predeterminedlocation associated with the fixed mesh network communications devicethat is in communication with the selected asset-specific locationdevice.
 2. The system of claim 1, wherein each of the plurality of fixedmesh network communications devices each comprise: a. a power source; b.a mesh network communication device electrically coupled to the powersource; and c. a memory that stores a fixed mesh network communicationsdevice identification.
 3. The system of claim 1, wherein theasset-specific location device comprises: a. a power source; b. a meshnetwork communication device electrically coupled to the power source;c. a memory circuit that stores the asset-specific identification; andd. a processor, electrically coupled to the power source, incommunication with the memory circuit and the mesh network communicationdevice, the processor programmed to execute the following steps: i. ifan asset identification message is received from the fixed mesh networkcommunication device, then compare an asset identification included inthe asset identification message to the asset-specific identificationstored in the memory; and ii. when the asset identification included inthe asset identification message corresponds to the asset-specificidentification stored in the memory, then transmit an asset foundmessage to the fixed mesh network communication device.
 4. The system ofclaim 1, wherein the asset-specific location device is embedded in theat least one of the mobile assets.
 5. The system of claim 1, wherein theasset-specific location device is affixed to the at least one of themobile assets.
 6. The system of claim 1, wherein the mobile assetscomprise personal mobility devices and wherein the predefined areacomprises an airport.
 7. The system of claim 1, wherein the mobileassets comprise shopping carts and wherein the predefined area comprisesa parking lot.
 8. A system for locating mobile assets within an airport,comprising: a. a plurality of fixed mesh network communications deviceseach disposed in a different area of the airport; b. a wheel chair thatis coupled to a wheel chair-specific location device, wherein the wheelchair-specific location device is configured to communicate a wheelchair-specific identification to a nearest one of the plurality of fixedmesh network communications devices via a mesh network, each wheelchair-specific location device including: i. a power source; ii. a meshnetwork communication device electrically coupled to the power source;iii. a memory circuit that stores the wheel chair-specificidentification; and iv. a processor, electrically coupled to the powersource, in communication with the memory circuit and the mesh networkcommunication device, the processor programmed to execute the followingsteps: (1) if a wheel chair identification message is received from thefixed mesh network communication device, then compare a wheel chairidentification included in the wheel chair identification message to thewheel chair-specific identification stored in the memory; and (2) whenthe wheel chair identification included in the wheel chairidentification message corresponds to the wheel chair-specificidentification stored in the memory, then transmit a wheel chair foundmessage to the fixed mesh network communication device; and c. acomputer, in communication with each of the fixed mesh networkcommunications devices that is configured to: i. receive from a user arequest for a location of a selected wheel chair; ii. poll each of theplurality of fixed mesh network communications devices to determinewhich of the plurality of fixed mesh network communications devices isin communication with a selected wheel chair-specific location devicethat is in affixed to the selected one of the wheel chairs; and iii.identify to the user the predetermined location associated with thefixed mesh network communications device that is in communication withthe selected wheel chair-specific location device.
 9. The system ofclaim 8, wherein each of the plurality of fixed mesh networkcommunications devices each comprise: a. a power source; b. a meshnetwork communication device electrically coupled to the power source;and c. a memory that stores a fixed mesh network communications deviceidentification.
 10. A system for locating assets in a parking lot,comprising: a. a plurality of fixed mesh network communications deviceseach disposed in a different area of the parking lot; b. a shopping cartthat is coupled to a shopping cart-specific location device, wherein theshopping cart-specific location device is configured to communicate ashopping cart-specific identification to a nearest one of the pluralityof fixed mesh network communications devices via a mesh network, eachshopping cart-specific location device including: i. a power source; ii.a mesh network communication device electrically coupled to the powersource; iii. a memory circuit that stores the shopping cart-specificidentification; and iv. a processor, electrically coupled to the powersource, in communication with the memory circuit and the mesh networkcommunication device, the processor programmed to execute the followingsteps: (1) if a shopping cart identification message is received fromthe fixed mesh network communication device, then compare a shoppingcart identification included in the shopping cart identification messageto the shopping cart-specific identification stored in the memory; and(2) when the shopping cart identification included in the shopping cartidentification message corresponds to the shopping cart-specificidentification stored in the memory, then transmit a shopping cart foundmessage to the fixed mesh network communication device; and c. acomputer, in communication with each of the fixed mesh networkcommunications devices that is configured to: i. receive from a user arequest for a location of a selected wheel chair; ii. poll each of theplurality of fixed mesh network communications devices to determinewhich of the plurality of fixed mesh network communications devices isin communication with a selected wheel chair-specific location devicethat is in affixed to the selected one of the shopping carts; and iii.identify to the user the predetermined location associated with thefixed mesh network communications device that is in communication withthe selected shopping cart-specific location device.
 11. The system ofclaim 10, wherein each of the plurality of fixed mesh networkcommunications devices each comprise: a. a power source; b. a meshnetwork communication device electrically coupled to the power source;and c. a memory that stores a fixed mesh network communications deviceidentification.
 12. A method of locating mobile assets within apredefined area, comprising the actions of: a. transmitting from acentral station an asset identification to a plurality of fixed meshnetwork communications devices associated with a different predeterminedlocation within the predefined area; b. transmitting the assetidentification from each fixed mesh network communications device; c.receiving a response, at one fixed mesh network communication device,from at least one asset-specific location device affixed to at least oneof the mobile assets that indicates that the at least one asset-specificlocation device has stored therein the asset identification; and d.transmitting from the one fixed mesh network communication device to thecentral station an indication that the one fixed mesh networkcommunication device has received the asset identification from the atleast one asset-specific location device.
 13. The method of claim 12,wherein the central station comprises a computer in communication witheach of the fixed mesh network communications devices.
 14. The method ofclaim 13, wherein the computer is programmed to indicate to a user alocation of the mobile asset based on an identification of the fixedmesh network communication device that transmitted the indication.